Method of arranging particulates liquid crystal display, and anistropic conductive film

ABSTRACT

This invention has its objects to provide a provide a fine particle arranging method which can accurately control the arrangement of fine particles. 
     This invention is related to a fine particle which comprises arranging method which comprises arranging charged fine particles on a surface of an object, 
     wherein areas having a relatively high electric potential (+(positive)) and areas having a relatively low electric potential (−(negative)) are alternately formed on said surface of the object, electric lines of force are formed based upon the areas having the relatively high electric potential (+(positive)) and the areas having the relatively low electric potential (−(negative)), and the fine particles are arranged at a relatively +(positive) bottom (1) position and/or a relatively −(negative) bottom (2) position of said electric lines of force.

FIELD OF THE INVENTION

The present invention relates to a fine particle arranging method, and aliquid crystal display and an anisotropic conductive film obtained bysuch a method.

BACKGROUND OF THE INVENTION

Along with the development of the electronics technology, fine particleshave come to be widely used in various fields. With respect to such fineparticles, for example, conductive fine particles used for anisotropicconductive films, etc., conductive fine particles used in the field ofbonding technology and fine particles used for spacers, etc. in liquidcrystal displays are listed. Liquid crystal displays form one of themajor fields for the application of the fine particles, and the liquidcrystal displays have been widely used, for example, in personalcomputers, portable electronic devices, etc. In general, as illustratedFIG. 11, the liquid crystal display comprises with two substrates 1provided with a color filter 4, a black matrix 5, a transparentelectrode 3, an alignment film 9 thereon, etc. and a liquid crystal 7interpolated between these two substrates 1. In this case, the membersregulating the gap between the two substrates 1 so as to properlymaintain the thickness of the liquid crystal layer are spacers 8.

In a conventional manufacturing method for liquid crystal displays,spacers are sprayed uniformly and at random on a substrate bearing pixelelectrodes; therefore, as illustrated in FIG. 11, spacers tend to beplaced on the pixel electrodes, that is, on the display section of theliquid crystal display. The spacers are generally formed by a materialsuch as a synthetic resin and glass, and if such spacers are placed onthe pixel electrodes, the spacer portions tend to cause light leakagedue to depolarization effect. Moreover, light void occurs due to thedisturbance of the orientation of the liquid crystal on the spacersurfaces, resulting in degradation in contrast and color tones, andsubsequent degradation in the display quality.

In order to solve the above-mentioned problem, an attempt is made toplace the spacers only on the black matrix portions that formlight-shielding films. The black matrix is provided in order to improvethe display contrast of the liquid crystal display and, in the case ofthe TFT-type liquid crystal display, to prevent the elements frommalfunctioning optically due to external light.

With respect to the technique for placing the spacers only on the blackmatrix portions, that is, portions other than the pixel electrodes ofthe liquid crystal display, Japanese Kokai Publication Hei-4-256925discloses a method which comprises holding the gate electrode and thedrain electrode at the same electric potential at the time of sprayingthe spacers. Moreover, Japanese Kokai Publication Hei-5-53121 disclosesa method which comprises applying a voltage to the wiring electrodes atthe time of spraying the spacers. Furthermore, Japanese KokaiPublication Hei-5-61052 discloses a method which comprises applying apositive voltage to the wiring electrodes with the spacers beingnegatively charged and sprayed in a dry system.

However, all of these methods are arranging techniques that utilize thewiring electrodes. In other words, all of these methods are designed todeal with the TFT-type liquid crystal display in the classification ofliquid crystal displays. Therefore, these arranging techniques are notapplied to the STN-type liquid crystal display which has no electrodescorresponding to the wiring electrodes and in which striped electrodes,as they are, form pixel electrodes by being arranged orthogonal to eachother on upper and lower substrates.

In the liquid crystal display, the necessity of arranging the spacers(one kind of fine particles) on accurate positions has been describedabove, and in the other fields of the application of fine particles,techniques for arranging fine particles on accurate positions have beendemanded. For example, in the case that an anisotropic conductive filmis manufactured by using conductive fine particles, it is also necessaryto accurately arrange the conductive fine particles so as to obtain anaccurate anisotropy and to prevent short-circuiting in the lateraldirection.

Here, with respect to techniques for controlling the arrangement of fineparticles, techniques such as an electrostatic powder coating method,which comprises forming a coated film by charged fine particles in astate where electric lines of force are formed between the dischargingportion of the corona discharge gun or tribo-gun and a target to becoated, have been known.

However, even if charged fine particles are sprayed on fine electrodesby using the corona discharge gun or the tribo-gun, it is difficult toprovide accurate control of the arrangement, and even with theapplication of these techniques, it is difficult to accurately controlthe arrangement of spacers in manufacturing liquid crystal displays andto manufacture anisotropic conductive films with high performances.

SUMMARY OF THE INVENTION

The objective of the present invention is to solve the above-mentionedproblems, thus to provide a fine particle arranging method in which thearrangement of fine particles can be accurately controlled, a liquidcrystal display and an anisotropic conductive film which are obtained byusing said method.

The first invention is a fine particle arranging method which comprisesarranging charged fine particles on a surface of an object, whereinareas having a relatively high electric potential (+(positive)) andareas having a relatively low electric potential (−(negative)) arealternately formed on said surface of the object, electric lines offorce are formed based upon the areas having the relatively highelectric potential (+(positive)) and the areas having the relatively lowelectric potential (−(negative)), and the fine particles are arranged atrelatively +(positive) bottom (1) positions and/or relatively−(negative) bottom (2) positions of said electric lines of force.

The second invention is a fine particle arranging method which comprisesarranging fine particles on portions other than the electrodes on thesurface of an object by spraying charged fine particles on the objectconstituted by aligning plural electrodes on the surface thereof,wherein spraying said fine particles is carried out while areas having arelatively high electric potential (+(positive)) and areas having arelatively low electric potential (−(negative)) are alternately formedon said electrode by applying voltages having different voltage valuesonto the plural aligned electrodes, and applying said voltages havingdifferent voltage values is carried out based upon a constantapplication pattern in which at least one of a relatively +(positive)bottom (1) position and a relatively −(negative) bottom (2) position ofelectric lines of force is made coincident with a gap position betweensaid plural electrodes, said electric lines of force being formed basedupon the voltages having different voltage values applied to the pluralelectrodes.

The third invention is a fine particle arranging method which comprisesarranging fine particles on electrodes by spraying charged fineparticles on an object constituted by aligning plural electrodes on thesurface thereof, wherein spraying said fine particles is carried outwhile areas having a relatively high electric potential (+(positive))and areas having a relatively low electric potential (−(negative)) arealternately formed by applying voltages having different voltage valuesonto the plural aligned linear electrodes, and applying the voltageshaving different voltage values is carried out based upon a constantapplication pattern in which at least one of a relatively +(positive)bottom (1) position and a relatively −(negative) bottom (2) position ofelectric lines of force is made coincident with a position on saidelectrode, said electric lines of force being formed based upon thevoltages having different voltage values applied to plural electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual drawing that explains a fine particle arrangingmethod of the present invention.

FIG. 2 is a conceptual drawing that explains the fine particle arrangingmethod of the present invention.

FIG. 3 is a conceptual drawing that shows areas having a relatively highelectric potential (+(positive)) and areas having a relatively lowelectric potential (−(negative)) formed on striped transparentelectrodes, when viewed from above the striped transparent electrodes.

FIG. 4 is a conceptual drawing that shows electric lines of force formedby those areas having an electric potential difference as shown in FIG.3, when viewed from above the striped transparent electrodes.

FIG. 5 is a conceptual drawing that explains one embodiment of amanufacturing method of a liquid crystal display of the presentinvention.

FIG. 6 is a conceptual drawing that explains an embodiment of amanufacturing method of a liquid crystal display of the presentinvention.

FIG. 7 is a conceptual drawing that explains an embodiment of amanufacturing method of a liquid crystal display of the presentinvention.

FIG. 8 is a conceptual drawing that explains an embodiment of amanufacturing method of a liquid crystal display of the presentinvention.

FIG. 9 is a conceptual drawing that explains one embodiment of amanufacturing method of an anisotropic conductive film of the presentinvention.

FIG. 10 is a schematic drawing of a comb-shaped electrode used in theExamples.

FIG. 11 is a conceptual cross-sectional view that shows a conventionalliquid crystal display.

EXPLANATION OF THE REFERENCE NUMERALS 1 substrate 2 polarizing plate 3transparent electrode 4 color filter 5 black matrix 6 overcoat 7 liquidcrystal 8 spacer 9 alignment film 10  container main body 11  spacerdischarging tube 12  voltage applying device

DETAILED DESCRIPTION OF THE INVENTION

The following description will discuss the present invention in detail.

The first invention is a fine particle arranging method which comprisesarranging charged fine particles on a surface of an object, whereinareas having a relatively high electric potential (+(positive)) andareas having a relatively low electric potential (−(negative)) arealternately formed on the surface of said object, electric lines offorce are formed based upon the areas having the relatively highelectric potential (+(positive)) and the areas having the relatively lowelectric potential (−(negative)), and the fine particles are arranged ata relatively +(positive) bottom (1) position and/or a relatively−(negative) bottom (2) position of said electric lines of force.

The first invention is a fine particle arranging method which comprisesarranging charged fine particles on a surface of an object.

With respect to the fine particles used in the first invention are notparticularly limited, there can be mentioned, for example, syntheticresin fine particles, inorganic fine particles, fine particlescomprising a synthetic resin with a pigment dispersed therein, fineparticles colored by a dye, and fine particles bonded by heat, light,etc. Moreover, the shape of the above-mentioned fine particles is notparticularly limited, and for example, a spherical shape and a polygonalshape are mentioned. The particle size of the above-mentioned fineparticles is not particularly limited, and in the case of spherical fineparticles, those having a size approximately in the range of 0.1 μm toseveral hundreds μm can be used.

The method for charging the above-mentioned fine particles is notparticularly limited, but there can be mentioned a method, for example,which comprises blowing out fine particles through a pipe, orifice,tube, etc. composed of metal, resin, etc. by using compressed air,nitrogen gas, etc. The fine particles thus blown out are charged byrepeating contacts (collisions) against the pipe walls. Moreover, therecan be mentioned a method which comprises stirring iron powder carrier,etc. to be charged, and then blowing out.

The object of the first invention is a target object on the surface ofwhich fine particles are arranged. Said object is not particularlylimited, and for example, those comprising synthetic resin, metal, etc.are used. The surface shape of the object is not particularly limited,and for example, a flat face and a non-flat face such as a curved faceand a concavo-convex face, can be mentioned.

Moreover, in order to form areas having a relatively high electricpotential (+(positive)) and areas having a relatively low electricpotential (−(negative)), a thin-film electrode pattern may be formed onthe surface thereof. Furthermore, a conductive member, etc. may beembedded in the surface of the object. In this case, the shape of thethin-film electrode or the conductive member is not particularlylimited, but there can be mentioned, for example, a striped shape havingstripes aligned therein, a lattice shape, a round shape, a wave shape,etc.

The fine particle arranging method of the first invention is a methodwhich comprises controlling and arranging the fine particles on thesurface of an object by alternately forming areas having a relativelyhigh electric potential (+(positive)) and areas having a relatively lowelectric potential (−(negative)).

In order to form a pattern having such areas, for example, voltageshaving different voltage values are applied onto a plurality of linearelectrodes aligned in parallel with each other based upon a constantapplication pattern. This constant application pattern is formed by atleast three electrodes. If only two electrodes are provided, electriclines of force are only formed from the electrode charging relatively+(positive) toward the electrode charging relatively −(negative),therefore, charged fine particles are arranged over the entire surfaceof either of the electrodes, thereby failing to control the arrangementof the fine particles. In the first invention, at least one of the areashaving a relatively high electric potential (+(positive)) and the areashaving a relatively low electric potential (−(negative)) can be formedby applying a voltage to the conductive member. In other words, aplurality of conductive members are formed on the surface of the objectand different voltages are applied to the respective conductive members.

In the first invention, at least one of the areas having a relativelyhigh electric potential (+(positive)) and the areas having a relativelylow electric potential (−(negative)) maybe formed by static electricity,and for example, frictional static charge, etc. by using objectsbelonging to different static charge series may be used to form theseareas.

In the first invention, at least one of the areas having a relativelyhigh electric potential (+(positive)) and the areas having a relativelylow electric potential (−(negative)) are also formed by means ofelectrostatic induction or dielectric polarization. When a method whichcomprises applying a voltage to the conductive member, a method whichcomprises using static electricity, a method which comprises usingelectrostatic induction or dielectric polarization, and a method whichcomprises using striped electrodes constituted by linear electrodes, aswill be described later, are adopted, two or more kinds of them may beused in a shared manner.

When the areas having a relatively high electric potential (+(positive))and the areas having a relatively low electric potential (−(negative))are alternately formed on the surface of an object, electric lines offorce are formed due to the difference in electric potential. Whencharged fine particles having a particle size of several μm to severaltens μm, such as spacers, are placed in an electric field having suchelectric lines of force, these fine particles are subjected to force bythe electric lines of force. Since the electric lines of force formrelatively +(positive) bottoms (1) and/or relatively −(negative) bottoms(2), the above-mentioned fine particles are arranged at these positionsof the relatively +(positive) bottoms (1) and/or the relatively−(negative) bottoms (2) depending on relative polarities of theircharge.

The fine particle arranging method of the first invention, which isdesigned as described above, makes it possible to accurately arrangefine particles on the surface of an object.

The second invention is a fine particle arranging method which comprisesarranging fine particles on portions other than the electrodes on thesurface of an object by spraying charged fine particles on the objectconstituted by aligning plural electrodes on the surface thereof,wherein spraying said fine particles is carried out while areas having arelatively high electric potential (+(positive)) and areas having arelatively low electric potential (−(negative)) are alternately formedon said electrodes by applying voltages having different voltage valuesonto a plurality of arranged electrodes, applying the voltages havingdifferent voltage values is carried out based upon a constantapplication pattern in which at least one of a relatively +(positive)bottom (1) position and a relatively −(negative) bottom (2) position ofelectric lines of force is made coincident with a gap position betweenplural electrodes, said electric lines of force being formed based uponthe voltages having different voltage values applied to the pluralelectrodes.

The fine particle arranging method of the second invention is a methodwhich comprises arranging fine particles on portions other than theelectrodes on the surface of an object by spraying charged fineparticles on an object composed of a plurality of electrodes aligned onthe surface thereof.

With respect to the object, fine particles, the method for charging thefine particles and the method for alternately forming the areas having arelatively high electric potential (+(positive)) and the areas having arelatively low electric potential (−(negative)) of the second invention,those explained in the first invention can be adopted in the samemanner.

The electrodes used in the second invention are not particularlylimited, and for example, linear electrodes, etc. may be used. Moreover,striped electrodes composed of those linear electrodes aligned inparallel with each other may be formed on the object.

The method for spraying the above-mentioned fine particles is notparticularly limited, but there can be mentioned, for example, a methodwhich comprises discharging fine particles through a pipe, orifice,tube, etc. composed of metal, resin, etc. by using compressed air,nitrogen gas, etc.

In general, when two kinds of voltages having different voltage valuesare respectively applied to two electrodes formed on a plane surface,areas having a relatively high electric potential (+(positive)) andareas having a relatively low electric potential (−(negative)) areformed. Electric lines of force are formed by the difference in theseelectric potentials. In other words, even in the case that both of thevoltages to be applied to the two electrodes have the same polarity withrespect to earth electric potential (ground electric potential) as areference (0), when there is an electric potential difference betweenthe voltages applied to the two electrodes, one of the electrodesbecomes relatively +(positive) so that areas having a relatively highelectric potential (+(positive)) are formed, and the other electrodebecomes relatively −(negative) so that areas having a relatively lowelectric potential (−(negative)) are formed. In this case, the electriclines of force are formed from the electrode that is relatively+(positive) toward the electrode that is relatively −(negative). In thecase that charged particles are placed in an electric field having suchelectric lines of force, if they are +(positively) charged, they aresubjected to a force in the direction of the electric lines of force,and if they are −(negatively) charged, they are subjected to a force ina direction reversed to the direction of the electric lines of force.

In the fine particle arranging method of the second invention, voltageshaving different voltage values are applied to the above-mentionedplural aligned electrodes so that, of those plural electrodes,electrodes having a relatively high electric potential (+(positive)) andelectrodes having a relatively low electric potential (−(negative)) areformed; thus, as illustrated in (I) of FIG. 1, areas having a relativelyhigh electric potential (+(positive)) and areas having a relatively lowelectric potential (−(negative)) are alternately formed on said pluralelectrodes. Here, with respect to the voltages having different voltagevalues, two kinds, or three kinds or more voltages, may be used. Ifthere are not less than three kinds of voltages having different values,it becomes difficult to form an electrode pattern; therefore, two kindsof voltages having different voltage values are preferably used.Moreover, the kinds of voltage to be applied to the electrodes is notparticularly limited, and for example, a voltage such as a DC voltageand a pulse voltage is preferably used. Moreover, the above-mentionedplural electrodes may be provided as striped electrodes formed byarranging linear electrodes with constant intervals.

As illustrated in (I) of FIG. 1, when an area having a relatively lowelectric potential (−(negative)), an area having a relatively highelectric potential (+(positive)), an area having a relative relativelyhigh electric potential (+(positive)) and an area having a relativelylow electric potential (−(negative)) are alternately formed on stripedelectrodes composed of four linear electrodes, electric lines of force,shown in (II) of FIG. 1, are formed on the striped electrodes. In thepresent invention, the application of the voltages is carried out basedupon a constant application pattern in which at least one of arelatively +(positive) bottom (1) position and a relatively −(negative)bottom (2) position of the above-mentioned electric lines of forceformed as mentioned above is made coincident with a gap position betweensaid plural linear electrodes. Here, the relatively +(positive) bottom(1) refers to a bottom a in (II) of FIG. 1. In (II) of FIG. 1, therelatively +(positive) bottom (1) is made coincident with a gap positionbetween said plural linear electrodes. In this case, supposing that theelectrodes charging relatively +(positive) are indicated by “+” and theelectrodes charging relatively −(negative) are indicated by “−” theabove-mentioned constant application pattern is represented by −++−

In the case that the fine particles to be sprayed are −(negatively)charged, since they are subjected to a force in the direction reversedto that of said electric lines of force, the fine particles are arrangedat the relatively +(positive) bottom (1), that is, at the gap betweenthe relatively +(positive) electrodes, in a line shape. Here, in thecase that the fine particles are relatively +(positively) charged, thesame effect can be obtained by reversing the relatively +(positive)electrodes and the relatively −(negative) electrodes.

Supposing that the fine particles are −(negatively) charged, that linearelectrodes having the same width are arranged with constant intervals sothat striped electrodes are formed, and that the even number ofrelatively +(positive) electrodes are continuously arranged, that is,for example, the constant application pattern is indicated by ,++−++−++− . . . , ++−−++−−++−− . . . , −−++++−−++++−− . . . , etc., thecontinuously arranged relatively +(positive) electrodes form an areahaving a relatively high electric potential (+(positive)), and thecontinuously arranged relatively −(negative) electrodes form an areahaving a relatively low electric potential (+(negative)), with theresult that since the relatively +(positive) bottom (1) is madecoincident with a gap position of the even number of the relatively+(positive) electrodes, the fine particles are arranged at the gapbetween the even number of relatively +(positive) electrodes.

With respect to the relationship between the charged particles and thevoltage polarities giving an electric potential difference, provision ismade so as to maintain the magnitude relationship between the voltagevalues forming the relatively high +(positive) electric potential andthe voltage values forming the relatively low −(negative) electricpotential, and the polarities of the voltage values giving a relativelyhigh electric potential +(positive) and a relatively low electricpotential −(negative) may be +(positive) and −(negative), or both ofthem may be +(positive), or both of them maybe −(negative). Moreover,either of them may be set to earth electric potential. For example, whenthe fine particles are −(negatively) charged, both of the voltagepolarities giving the electric potential difference may be −(negative).In this case, although the number of fine particles to reach thesubstrate tends to decrease slightly; the fine particles are arrangedwithout being subjected to repulsion due to the influence of theelectric lines of force. Even in the case of the fine particles+(positively) charged, the voltage polarities do not matter as long asthe magnitude relationship between the voltage values is maintained inthe same manner. These voltage application conditions are appropriatelydetermined depending on factors such as the gap between the electrodesto be used and the quantity of charge of the fine particles.

In the relationship in which the electric potential between theelectrodes arranging the fine particles have a polarity reversed to thecharging polarity of the fine particles, when the electric potentialdifference is further increased so that the fine particles are moreeffectively made coincident with the electric lines of force, thepositioning property may be improved in some cases.

Moreover, in the relationship in which the electric potential of theelectrodes is the same as the charging polarity of the fine particles,it is possible to improve the positioning property in some cases. Forexample, even in the case that the charging polarity of the fineparticles is −(negative), it is better for the positioning property toform an electric potential difference of 100 V by using voltages from−1100 to −1000 V with the same polarity as the charging polarity of thefine particles than to form the electric potential difference of 100 Vby using voltages from 0 to +100 V. This is because in the case that theelectric potential difference is formed by using the reversed chargingpolarity of the fine particles, the fine particles is first subjected tothe pull of gravity in the distance from the substrate so that theirfalling speed tends to increase, while in the case that the electricpotential difference is formed by using the same charging polarity asthe fine particles, their falling speed tends to decrease due to therepulsive force, with the result that the inertial force exerting on thefine particles varies so that the behavior of aligning the fineparticles with the electric lines of force is allowed to change.

The fine particle arranging method of the second invention, which isdesigned as described above, makes it possible to accurately arrangefine particles on the surface of an object.

Here, the electrodes used in the present invention are not limited tolinear electrodes, and those electrodes of the picture character displaytype, etc. may be adopted.

The third invention is a fine particle arranging method which comprisesarranging fine particles on electrodes by spraying charged fineparticles on an object constituted by aligning plural electrodes on thesurface thereof, wherein spraying said fine particles is carried outwhile areas having a relatively high electric potential (+(positive))and areas having a relatively low electric potential (−(negative)) arealternately formed by applying voltages having different voltage valuesonto the plural arranged electrodes, the applying the voltages havingdifferent voltage values on said electrodes is carried out based upon aconstant application pattern in which at least one of arelatively+(positive) bottom (1) position and a relatively −(negative)bottom (2) position of electric lines of force is made coincident with aposition on each electrode, said electric lines of force are formedbased upon the voltages having different voltage values applied to saidplural electrodes.

The fine particle arranging method of the third invention is thearranging method which comprises arranging fine particles on electrodesby spraying charged fine particles on an object constituted by aligningplural electrodes on the surface thereof. With respect to the positionon which the fine particles are arranged, it is not necessarily theentire surface of the electrode, and may be only a specific portion onthe surface of said electrode.

In the third invention, with respect to the object, fine particles, themethod for charging the fine particles and the method for alternatelyforming the areas having a relatively high electric potential(+(positive)) and the areas having a relatively low electric potential(−(negative)), there can be mentioned the same as explained in the firstand second inventions.

With respect to the electrodes of the third invention, the sameelectrodes as explained in the second invention can be mentioned.

With respect to the spraying methods of the fine particles of the thirdinvention, there can be mentioned the same methods as explained in thesecond invention.

In the fine particle arranging method of the third invention, voltageshaving different voltage values are applied to the above-mentionedplural aligned electrodes so that, of those electrodes, electrodeshaving a relatively high electric potential (+(positive)) and electrodeshaving a relatively low electric potential (−(negative)) are formed;thus, as illustrated in (I) of FIG. 2, areas having a relatively highelectric potential (+(positive)) and areas having a relatively lowelectric potential (−(negative)) are alternately formed. Here, withrespect to the number of voltages having different voltage values, thekinds of the voltage to be applied to the electrodes, and the pluralelectrodes mentioned above are the same as those explained in the secondinvention.

As illustrated in (I) of FIG. 2, when an area having a relatively lowelectric potential (−(negative)), an area having a relatively highelectric potential (+(positive)) and an area having a relatively lowelectric potential (−(negative)) are alternately formed on stripedelectrodes composed of three linear electrodes, electric lines of force,shown in (II) of FIG. 2, are formed on the striped electrodes. In thepresent invention, the application of the voltages having differentvoltage value is carried out based upon a constant application patternin which at least one a relatively +(positive) bottom (1) position and arelatively −(negative) bottom (2) position of the above-mentionedelectric lines of force is made coincident with a gap position betweenthe plural linear electrodes. Here, the relatively +(positive) bottom(1) refers to a bottom a in (II) of FIG. 2. In (II) of FIG. 2, therelatively +(positive) bottom (1) is made coincident with a position onsaid plural linear electrodes. In this case, the above-mentionedconstant application pattern is represented by −+−.

In the case that the fine particles to be sprayed are −(negatively)charged, since they are subjected to a force in the direction reversedto that of the electric lines of force, the fine particles are arrangedat the relatively +(positive) bottom (1), that is, on the electrodecharging relatively +(positive) in a line shape. Here, in the case thatthe fine particles are relatively+(positively) charged, the same effectcan be obtained by reversing the relatively +(positive) electrodes andthe relatively −(negative) electrodes.

Supposing that the fine particles are −(negatively) charged, that linearelectrodes having the same width are aligned with constant intervals sothat striped electrodes are formed, and that the odd number ofrelatively +(positive) electrodes are continuously aligned, for example,the constant application pattern is indicated by, −−+−−+−− . . .+++−+++− . . . , etc., the relatively +(positive) bottom (1) iscoincident with a position of an electrode located in the center of theodd number of the relatively +(positive) electrodes, with the resultthat the fine particles are arranged in the center of this electrode ina line shape.

The fine particle arranging method of the third invention, which isdesigned as described above, makes it possible to accurately arrangefine particles on the surface of an object.

In the second invention and the third invention, in the case that thewidths of the linear electrodes are not equal, for example, when theconstant application pattern is indicated by: ++−++−++− . . . , ++−−++−−. . . , ++++−−++++−− . . . , etc., those aligned electrodes chargingrelatively +(positive) are allowed to form an area having a relativelyhigh electric potential (+(positive)), and those aligned electrodescharging relatively −(negative) are allowed to form an area having arelatively low electric potential (−(negative)) in the same manner asthe electrodes having the same width; therefore, as a whole, the areahaving a relatively high electric potential (+(positive)) and the areahaving a relatively low electric potential (−(negative)) are alternatelyarranged. However, in this case, the relatively +(positive) bottom (1)in the electric lines of force is not necessarily formed in the centerposition of the area having a relatively high electric potential(+(positive)); and the bottom position of the electric lines of forcevaries depending on the degree of difference in the electrode width, therelationship with the electrode intervals at the time in question, theregularity of the electrode widths, etc. Therefore, even in the case ofthe odd number of aligned electrodes charging relatively +(positive),the −(negatively) charged fine particles can be placed at a positionwithout any electrode by adjusting the electrode width, the electrodeinterval, the voltage application method, etc. In contrast, even in thecase of the above-mentioned constant application pattern (even number of+), the −(negatively) charged fine particles can be placed on theelectrode.

Moreover, in the case that, although the linear electrodes have the samewidth, they are not arranged with the same interval, the position of thebottom of the electric lines of force varies depending on the degree ofdifference in the interval, the regularity of the intervals, etc.Therefore, the electrode interval or the arrangement on the electrodecan be determined by taking these factors into consideration.

Furthermore, for example, when voltages, such as −100 V, +300 V and −200V, are applied to three linear electrodes, the relatively+(positive)bottom (1) of the electric lines of force is formed at a position in thevicinity of a ⅓ of the center electrode, with the result that when−(negatively) charged fine particles are allowed to drop thereon, thefine particles are arranged on the corresponding position. For example,when voltages, such as −100 V, +100 V, +100 V, +100 V and −200 V, areapplied to five linear electrodes having a specific width and ainterval, the relatively +(positive) bottom (1) of the electric lines offorce is formed in the vicinity of the interval between the second andthird electrodes, with the result that fine particles are arranged onthe corresponding position.

The fine particle arranging methods of the first, the second and thethird inventions are preferably applied to the manufacturing method ofliquid crystal displays. In other words, liquid crystal displays can beobtained by spraying spacers by using the fine particle arranging methodof the first, the second or the third invention.

In general, a liquid crystal display is manufactured by spraying spacerson a first substrate having striped transparent electrodes constitutedby arranging a plurality of linear transparent electrodes in parallelwith each other, placing a second substrate on the first substrate so asto face it, and injecting liquid crystal to the gap between them. Aliquid crystal display of the present invention 2 is obtained byapplying the fine particle arranging method of the present invention 1to spraying spacer on the first substrate having the above-mentionedstriped transparent electrodes.

The liquid crystal display is, for example, manufactured in thefollowing processes.

Voltages having different voltage values are applied on a plurality oflinear transparent electrodes arranged with constant intervals toconstitute striped transparent electrodes on the first substrate, sothat, in the above-mentioned plural linear transparent electrodes, thoseelectrodes charging relatively +(positive) and those electrodes chargingrelatively −(negative) are formed; thus, as illustrated in FIG. 3, areashaving a relatively high electric potential (+(positive)) and areashaving relatively low electric potential (−(negative)) are alternatelyformed on the striped transparent electrodes constituted by the plurallinear transparent electrodes.

In this case, the areas having the electric potential differences shownin FIG. 3 form electric lines of force as illustrated in FIG. 4. In thepresent invention, the applying method of the voltages having differentvoltage values is carried out based upon a constant application patternin which at least one of a relatively +(positive) bottom (1) and arelatively −(negative) bottom (2) of the electric lines of force asformed mentioned above is made coincident with a position of the gapbetween plural linear transparent electrodes mentioned above. Here, therelatively +(positive) bottom (1) refers to a bottom a in FIG. 4, andthe relatively −(negative) bottom (2) refers to a bottom b in FIG. 4. InFIG. 4, the relatively +(positive) bottom (1) is made coincident with aposition of the gap between the plural linear transparent electrodesmentioned above.

Generally, in the manufacturing process of the liquid crystal display,as illustrated in FIG. 5, spraying the spacer is carried out by sprayingand scattering an appropriate amount of spacers on the substrate bymeans of compressed air, nitrogen, etc. As to the method for scatteringthe spacer, either a dry spraying method or a wet spraying method may beused. The wet spraying method comprises spraying the spacers bydispersing in a mixed solution such as water and alcohol, and in thiscase also, since the spacers are charged, the effects of the presentinvention are exerted without failure. However, since the greater thecharging quantity of the spacers, the higher the arranging precision,the dry spraying method is preferably adopted. By the spraying processmentioned above, the spacers are charged while they repeat contacting(colliding) the piping walls.

Therefore, when sprayed spacers are −(negatively) charged, they areplaced at the relatively +(positive) bottom (1), that is, at the gapbetween the plural linear transparent electrodes.

With respect to the spacers used in the above-mentioned liquid crystaldisplay, there can be mentioned the same spacers as explained in thefirst, second and third inventions.

In the above-mentioned liquid crystal display, the substrate on whichthe spacers are sprayed may be a substrate with a color filter or asubstrate opposing to the substrate in question.

In the case that the fine particle arranging methods of the first,second and third inventions are applied to the manufacturing method of aTFT-type liquid crystal display, striped electrodes are formed on asubstrate on the color filter side, and the spacers are arranged betweenelectrodes by utilizing these electrodes. In a general TFT-type liquidcrystal display, flat electrodes are used on the color filter sidesubstrate, and even in the case of using striped electrodes, the devicecan be driven in the same manner as the general TFT liquid crystaldisplay by applying voltages having the same electric potential to therespective linear electrodes constituting the striped electrodes.

The following description will discuss embodiments of theabove-mentioned liquid crystal display in detail.

Spacers can be sprayed on the gap between the adjacent two lineartransparent electrodes applied the voltage having the reversed polaritythereto, for example, by carrying out spraying the spacers whileapplying a voltage having a polarity reversed to the charging polarityof the spacers and a voltage having the same polarity as the chargingpolarity of the spacers to a plurality of linear transparent electrodesaligned in parallel with each other, and applying the voltages havingthe reverse polarity and the same polarity by the method such that thevoltage having the reversed polarity is applied to two lineartransparent electrodes, the voltage having the same polarity is appliedto one linear transparent electrode, and the voltages are applied toserve the arrangement of these adjacent three linear transparentelectrodes as one unit of repetition.

When the above-mentioned spacers are composed of, for example, asynthetic resin, they are generally negatively charged by repeatingcontacts (collisions) against the piping walls during the sprayingprocess. Therefore, when a negative voltage having the same polarity isapplied to the transparent electrodes, the spacers are repulsed by arepulsive force with the result that they are sprayed on portions otherthan the transparent electrodes. In contrast, when a positive voltagehaving the reversed polarity is applied, the spacers are sprayed ontothe transparent electrode by an attracting force in a concentratedmanner.

In the striped transparent electrodes constituted by a plurality of theparallel aligned linear transparent electrodes, positive voltages ornegative voltages are respectively applied to said plural lineartransparent electrodes (for example, referred to as a1, a2, a3, a4, a5,a6 . . . ).

In the above-mentioned arrangement, when the negative voltage and thepositive voltage are alternately applied to the plural lineartransparent electrodes, the spacers are sprayed on the center of thewidth of the transparent electrode to which the positive voltage hasbeen applied, due to duplicated functions of the repulsive force andattracting force.

Here, as illustrated in FIG. 6, when the respective applications arecarried out so that a set of two positive voltages (+) and one negativevoltage (−) is repeated, that is, in a manner so as to apply a positivevoltage to a1, a positive voltage to a2, a negative voltage to a3, apositive voltage to a4, a positive voltage to a5 and a negative voltageto a6, an electric field is formed between a1 and a2, between a4 and a5. . . etc. (one of the reasons for which is the small size of theelectrode interval between the respective transparent electrodes:approximately, 10 to 30 μm); therefore, the spacers are repulsed by arepulsive force from the negative voltage and also attracted by anattracting force from the positive voltage, as a result that those areaccurately sprayed on the center portion between the positive voltageapplied electrode and the positive voltage applied electrode. The centerportion between the positive voltage applied electrode and the positivevoltage applied electrode corresponds to the gap between the twoadjacent linear transparent electrodes to which the voltage having thereversed polarity to the charging polarity of the spacers has beenapplied, that is, the portions other than the pixel electrode.

With the above-mentioned operation, it becomes possible to accuratelyspray the spacers between a1 and a2, between a4 and a5, . . . , etc.,and also to set the spacers supplied to the same quantity between a1 anda2, between a4 and a5, . . . , etc.

In the above-mentioned operation, the spaying of the spacers is carriedout between a1 and a2, between a4 and a5, . . . , etc. accurately in auniform manner; however, with respect to the other gap portions such as,between a2 and a3, between a3 and a4, and between a5 and a6, it is notpossible to spray the spacers.

For this reason, the applications of the reversed polarity and the samepolarity are preferably carried out repeatedly so as to average theexistence of the gap between the two linear transparent electrodes onwhich the spacers are sprayed with respect to the plural lineartransparent electrodes.

In other words, it is preferable to further spray the spacers after theabove-mentioned operation while changing the combination of the positivevoltage and negative voltage of the applied electrodes. Morespecifically, after the above-mentioned operation, as illustrated inFIG. 7, the respective applications are carried out so that a set of twopositive voltages (+) and one negative voltage (−) is repeated, that is,in a manner so as to apply a negative voltage to a1, a positive voltageto a2, a positive voltage to a3, a negative voltage to a4, a positivevoltage to a5 and a positive voltage to a6 . . . . Thus, it becomespossible to accurately spray the spacers between a2 and a3, between a5and a6, . . . , etc.

Moreover, it is preferable to spray the spacers while changing thecombination of the positive voltage and negative voltage of the appliedelectrodes and then further to spray the spacers again while changingthe combination of the positive voltage and negative voltage of theapplied electrodes. More specifically, as illustrated in FIG. 8, therespective applications are carried out so that a set of two positivevoltages (+) and one negative voltage (−) is repeated, that is, in amanner so as to apply a positive voltage to a1, a negative voltage toa2, a positive voltage to a3, a positive voltage to a4, a negativevoltage to a5 and a positive voltage to a6 . etc. Thus, it becomespossible to accurately spray the spacers between a3 and a4, . . . , etc.

The above-mentioned two or three operations make it possible to placethe spacers on the gap between the electrodes extremely accurately anduniformly.

In other words, the above-mentioned spraying method of the spacers usesthe application methods of the voltages of the reversed polarity and thesame polarity which take the following three methods:

(1) a repetition is made in the sequence of reverse polarity, reversepolarity and same polarity,

(2) a repetition is made in the sequence of reverse polarity, samepolarity and reverse polarity, and

(3) a repetition is made in the sequence of same polarity, reversepolarity and reverse polarity.

The objective of the present invention is achieved by following any oneof said methods. Moreover, by using at least two of the three sequencesin an overlapped manner, it is possible to obtain better effects.

The liquid crystal display, obtained by using the fine particlearranging method of the first, second, or third invention, has theconstruction as described above; therefore, in the manufacturing processof the STN-type liquid crystal display also it is possible to remove ofthe pixel electrodes, and consequently to arrange the spacers on theblack matrix portion. Therefore, it is possible to eliminate lightleakage due to problems with the spacers, and to ensure very highcontrast.

The fine particle arranging methods of the first invention, the secondinvention and the third invention are also applicable to themanufacturing method of anisotropic conductive films. In other words,spraying the conductive fine particles by the use of the fine particlearranging methods of the first invention, the second invention and thethird invention, it is possible to obtain an anisotropic conductivefilm.

For example, the anisotropic conductive film is manufactured by using amethod shown in FIG. 9.

First, conductive fine particles are arranged on an electrodes of a filmon which electrodes are formed by using the fine particle arrangingmethod of the first invention or the second invention (FIG. 9(a)). Here,the use of the fine particle arranging method of the first invention orthe third invention also makes it possible to arrange the conductivefine particles on the portion without any electrodes.

With respect to the conductive fine particles, generally, fine particlescoated with Au, Ni, etc. on the surface thereof are used. Even amongmetals, since their charging series is different depending on the kindsof metals, they can be charged in the same manner as the resinparticles. For example, in the case that fine particles coated with Niare sprayed by using SUS pipes, they are positively charged. Therefore,these particles can be selectively arranged on the gap between theelectrodes or on the electrodes. Moreover, those particles coated withan insulating resin on the surface thereof can be used.

In the case of the conductive fine particles coated with an insulatingresin, the fine particles exhibit functions as general conductive fineparticles by fusing the insulating resin by heat at the final stage. Thecoating of the conductive fine particles by the use of the insulatingresin is carried out by, for example, loading the conductive fineparticles to a solution in which the above-mentioned insulating resinhas been dissolved, stirring them, then taking out, drying andpulverizing.

Next, an adhesive layer is transferred, and press-bonded to a film onwhich the conductive fine particles have been arranged (FIG. 9(b),9(c)). Further, an anisotropic conductive film is obtained byexfoliation of the film with electrodes being formed (FIG. 9(d)). Withrespect to the anisotropic conductive film thus formed, a plurality ofthem may be stacked. Moreover, this may be sliced at appropriatepositions when used.

The anisotropic conductive film is not liable to short-circuiting in thelateral direction. Moreover, it is possible to obtain an anisotropicconductive film which locally allows conduction in the lateral directionby further increasing the density of the conductive fine particles tomake the film conductive in the lateral direction.

The anisotropic conductive film obtained by using the fine particlearranging method of the first invention, the second invention or thethird invention, which has the above-mentioned construction, has theconductive fine particles only on the electrode portions requiringconductivity.

BEST MODES FOR CARRYING OUT THE INVENTION

The present invention will be explained in more detail by means ofexamples; however, the present invention is not intended to be limitedonly by these examples.

EXAMPLE 1

Micropearl BB (Particle size; 5 μm Sekisui Fine Chemical K.K.) was usedas fine particles. A spraying device as shown in FIG. 5 was used fordropping the fine particles onto an object. The fine particles of anappropriate amount was loaded into a diffuser, and diffused bycompressed air of 1.5 kgf/cm² and sprayed onto the surface of theobject. Here, this operation naturally allowed the fine particles to be−(negatively) charged. The spraying device was designed so that a DCvoltage was to be applied from a voltage applying device into the mainbody thereof by using needle shaped electrode terminals. With respect tothe object on which the fine particles were arranged, a glass substratewas prepared on which a ring pattern with four concentric circles,having an electrode width of 100 μm and an electrode interval of 20 μm,was formed with ITO. The circle in the center, composed of glass, had adiameter of 2 mm (these circles being referred to as A, B, C and D fromthe center).

A voltage of +100 V was applied to A and D from the needle shapedelectrode terminals, and a voltage of +300 V was applied to B and C.Thus, electric lines of force were formed with a relatively + bottom inthe shape of a circle between B and C.

When the fine particles were sprayed with this voltage state, the fineparticles were arranged in the shape of a circle on the gap between Band C.

EXAMPLE 2

In Example 1, except that voltages of +100 V, +300 V and +100 V wererespectively applied to A, B and C, the same operation as Example 1 wascarried out. In this state, the electric lines of force were formed witha relatively + bottom centered on the B electrode width.

As a result, the fine particles were arranged in the shape of a circlealong the center position of the B electrode width.

EXAMPLE 3

A plurality of striped electrodes having a width of 100 μm and a aninterval of 100 μm were formed on a polyimide resin substrate by usingITO. The polyimide resin surface bearing the ITO electrodes was rubbedby a nylon brush so that the polyimide resin surface was negativelycharged. Immediately after this process, a voltage of +500 V was appliedto the respective ITO electrodes and fine particles were sprayed in thesame manner as Example 1. In this state, electric lines of force wereformed with a relatively + bottom on a position of the center of eachITO electrode width.

As a result, the fine particles were linearly arranged on the positionof the center of each ITO electrode width.

EXAMPLE 4

A lattice pattern having an aperture section of 100×300 30 μm and a linewidth of 30 μm was formed on a glass substrate by using a Cr thin film.The substrate was subjected to closely contact a stage formed by Al, anda voltage of −500 V was applied to the Cr portion, while a voltage of +1kV was applied to the Al stage. The glass portion was brought to thesame state as if it was subjected to applying a + voltage due todielectric polarization caused by the voltage of the Al stage. In thisstate, electric lines of force were formed with relatively + bottoms ona position of the center of the aperture portion from four sides.

In this state, the fine particles were sprayed in the same manner asExample 1.

As a result, the fine particles were linearly arranged in the center ofthe aperture section.

COMPARATIVE EXAMPLE 1

Two linear ITO electrodes were formed on a glass substrate with a widthof 100 μm and an interval of 20 μm. A voltage of −100 V was applied toone of the electrodes and a voltage of +100 V was applied to the otherelectrode. In this state, electric lines of force were formed in a shapelike a mountain connecting the two electrodes.

In this state, the fine particles were sprayed in the same manner asExample 1.

As a result, the fine particles were arranged on the entire surfaces ofthe two electrodes to which the voltage of +100 V was applied.

COMPARATIVE EXAMPLE 2

Two linear ITO electrodes were formed on a glass substrate with a widthof 100 μm and a an interval of 20 μm. Voltages of +100 V were applied tothe two electrodes. In this state, electric lines of force weresupposedly formed in a shape like connecting the electrodes to distantplaces.

In this state, the fine particles were sprayed in the same manner asExample 1.

As a result, the fine particles were arranged on the entire surfaces ofthe two electrodes to which +100 V was applied and on the gap betweenthe electrodes.

COMPARATIVE EXAMPLE 3

Two linear ITO electrodes were formed on a glass substrate with a widthof 100 μm and a an interval of 20 μm. Voltages of −100 V were applied tothe two electrodes. In this state, electric lines of force weresupposedly formed in a shape like connecting the electrodes to distantplaces.

In this state, the fine particles were sprayed in the same manner asExample 1.

As a result, no fine particles were arranged on the surfaces of the twoelectrodes to which −100 V was applied and on the gap between the twoelectrodes. Here, the fine particles were repulsed, with the result thatonly few number of them were arranged on the substrates.

EXAMPLE 5

Copper wires having a diameter of 100 μm were secured and arranged ontoa plurality of pieces of paper in parallel with each other with aninterval of 100 μm and with respect to the copper wires thus arranged,voltages of +200 V were applied to two copper wires and voltages of −200V were applied to the next two copper wires in succession, and this setof processes was successively repeated. In this state, electric lines offorce were supposedly formed with a + bottom between two wires to whichthe voltages of +200 V were applied.

In this state, the fine particles were sprayed in the same manner asExample 1.

After the spraying process, the wires were removed, and the pieces ofpaper were observed. The results showed that the fine particles werearranged only the gap between the wires to which the voltages of +200 Vwere applied.

EXAMPLE 6

Common electrodes for use in an STN-type liquid crystal display (a colorfilter formation substrate having an aperture section of 80×285 μm foreach of the pixels RGB (Red, Green and Blue), a width of a black matrixline of 20 μm, an ITO electrode width of 290 μm, an electrode intervalof 15 μm and a plate thickness of 0.7 mm) were allowed to conductoutside the range of the display device so as to form comb-shapedelectrodes of 2:1 as illustrated in FIG. 10; thus, a substrate wasformed.

A polyimide alignment film of 0.05 μm was formed on the substrate, andthis was subjected to a rubbing treatment. Next, a voltage of +700 V wasapplied to a conductive section A on the two electrodes side of the 2:1comb-shaped electrodes, and a voltage of +500 V was applied to aconductive section B on the one electrode side. While the electricpotential difference of 200 V was maintained, spacers (fine particles)were discharged from the diffuser and sprayed on the substrate in thesame manner as Example 1.

In this state, electric lines of force were supposedly formed with a +bottom on the gap between the two electrodes to which +700 V wasapplied.

When the arranged state of the spacers spraying was observed, thespacers were linearly arranged on the ITO electrode portions on the twoelectrodes side of the 2:1 comb-shaped electrodes. The portion betweenthe ITO electrodes was coincident with a position under the blackmatrix. Therefore, the spacers were arranged beneath the black matrix.

The conductive section A and the conductive section B of the resultingsubstrate were cut off, and laminated with a segment electrode substrate(segment electrode: striped electrode having an ITO line width of 80 μmand an ITO interval of 15 μm) as a general common electrode substrate byusing a known method to form a liquid crystal display. This liquidcrystal display had superior contrast and provided high-quality images.

EXAMPLE 7

Segment electrodes for use in an STN-type liquid crystal display (havingan ITO electrode width of 80 μm, an interval of 15 μm and a platethickness of 0.7 mm) were allowed to conduct outside the range of thedisplay device in the same manner as Example 6 so that a comb-shapedelectrode construction of 2:1 as illustrated in FIG. 10 was provided.

A polyimide alignment film of 0.05 μm was formed on the substrate thusmanufactured, and this was subjected to a rubbing treatment.

When it is supposed that this is laminated with a color filter substratehaving the 2:1 comb-shaped electrodes, a voltage of +50V was applied tothe conductive section on the two-electrodes side corresponding to an RGstripe, while a voltage of +100 V was applied to the conductive sectionon the one-electrode side, and with the electric potential difference of150 V being maintained, spacers were discharged from the diffuser andsprayed on the substrate.

In this voltage state, a + bottom was supposedly formed on the positionin the center of the stripe electrode B.

After the spraying process, when the arranged state of the spacers wereobserved, they were linearly arranged in the center of the stripedelectrode width corresponding to B.

The conductive sections of the resulting substrate were cut off, andlaminated with a common electrode substrate as a general segmentelectrode substrate by using a known method to form a liquid crystaldisplay. In this liquid crystal display, although the colored layers ofthe respective colors RGB of the color filters were different inthickness, the spacers were arranged only on the B layer, thereby makingit possible to provide a liquid crystal display with a more uniform cellgap.

EXAMPLE 8

On a common electrode substrate for use in an STN-type liquid crystaldisplay (a color filter formation substrate having an aperture sectionof 80×285 μm for each of the pixels RGB (Red, Green and Blue), a widthof a black matrix line of 20 μm, an ITO electrode width of 80 μm, anelectrode interval of 15 μm and a plate thickness of 0.7 mm) was formeda polyimide alignment film of 0.05 μm, and this was subjected to arubbing treatment by using a nylon brush. As a result, the polyimidefilm was −(negatively) charged.

Successively, the needle shaped leading ends of prober were applied toevery other two of the linear striped electrodes of the commonelectrodes to apply voltages of +200 V.

In this state, electric lines of force were supposedly formed with a +bottom on the gap between the electrodes to which voltages of +200 Vwere applied.

In this state, spacers were discharged from the diffuser and sprayed onthe substrate in the same manner as Example 1.

When the substrate was observed after the spraying process, the spacerswere linearly arranged on the gap between the striped electrodes. Thus,the spacers were arranged beneath the black matrix.

The common electrode substrate thus obtained was laminated with asegment electrode substrate (segment electrodes: striped electrodeshaving an ITO line width of 80 μm and an ITO interval of 15 μm) by usinga known method to form a liquid crystal display.

As a result, it was possible to obtain high-quality images with goodcontrast.

In the construction of the common electrodes of the STN-type liquidcrystal display, conductive sections were formed on either side in thestripe direction in a manner as illustrated in FIG. 10, so that acomb-shaped electrode construction of 2:2 was formed. An alignment filmwas formed on the substrate, and this was subjected to a rubbingtreatment. Successively, a voltage applying device is connected to thetwo conductive sections, and a DC voltage of +700 V was applied to oneof the conductive sections, and a DC voltage of +500 V was applied tothe other conductive section.

In this state, electric lines of force were supposedly formed with a +bottom on the gap between the electrodes to which the voltage of +700 Vhad been applied.

While this state is maintained, the spacers were sprayed in the samemanner as Example 1. When the substrate was observed after the sprayingprocess by using a microscope, the spacers were linearly arranged on thegap between the striped electrodes to which the voltages (+700 V) hadbeen applied so as to form relatively +(positive).

Next, the voltage values were reversed so that a voltage of +500 V wasapplied to the one of the conductive sections and a voltage of +700 Vwas applied to the other conductive section, and the spacers weresprayed in the same manner as Example 1. When the substrate was observedafter the spraying process by using a microscope, the spacers werelinearly arranged on the gap between the striped electrodes differentfrom those formed in the first spraying process, to which the voltages(+700 V) had been newly applied so as to form relatively +(positive).

The portion between the electrodes was coincident with a position underthe black matrix. Therefore, the spacers were arranged beneath the blackmatrix.

The conductive sections of the resulting substrate were cut off, andlaminated with a common electrode substrate as a general segmentelectrode substrate by using a known method to form a liquid crystaldisplay, as a result that high-quality images with very high contrastwere obtained.

EXAMPLE 9

In an electrode construction of common electrodes for use in an STN-typeliquid crystal display (a color filter formation substrate having anaperture section of 80×280 μm for each of the pixels RGB (Red, Green andBlue), a width of a black matrix line of 40 μm, an ITO electrode widthof 285 μm, an electrode interval of 35 μm and a plate thickness of 0.7mm), conductive sections were formed on either side in the stripedirection in a manner as illustrated in FIG. 10, so that a comb-shapedelectrode construction of 2:1 was formed. A polyimide alignment film of0.05 μm was formed on the substrate, and this was subjected to a rubbingtreatment.

A voltage of −1000 V (relatively +) was applied to the two-electrodesside, and a voltage of −1100 V (relatively −) was applied to theone-electrode side of the 2:1 comb-shaped electrode construction.

In this state, electric lines of force were supposedly formed with arelatively + bottom on the gap between the two aligned electrodes towhich the voltage of −1000 V had been applied.

While this state is maintained, the spacers were discharged fromdiffuser and sprayed on the substrate in the same manner as Example 1.

When the substrate was observed after the spraying process, althoughboth the charging polarity of the spacers and the polarity of theapplied voltages were the same −(negative) polarity, the spacers werelinearly arranged on the gap between the striped electrodes withoutbeing repulsed by the electric lines of force. Thus, the spacers werearranged beneath the black matrix.

The common electrode substrate obtained as described above was laminatedwith a segment electrode substrate by using a known method, and theconductive sections were cut off, thereby forming a liquid crystaldisplay.

As a result, it was possible to obtain high-quality images with veryhigh contrast.

EXAMPLE 10

Micropearl SP—Ni (Particle size; 6 ∞m, Sekisui Fine Chemical K.K.) wasused as conductive fine particles. The dropping process of theconductive fine particles were carried out in the same manner asExample 1. Here, this operation naturally allowed the conductive fineparticles to be +(positively) charged.

A comb-shaped electrode construction of 2:1 as illustrated in FIG. 10was formed on a polyimide film by using ITO (ITO electrode width: 80 μm,electrode interval: 20 μm).

A voltage of −100 V was applied to the two-electrodes side of 2:1, and avoltage of +100 V was applied to the one-electrode side. Thus, arelatively − bottom was supposedly formed on the gap between two-sideelectrodes.

While this state was maintained, the fine particles were sprayed in thesame manner as Example 1.

As a result, the fine particles were linearly arranged on the gapbetween the two electrodes to which the voltage of −100 V had beenapplied.

Moreover, when the voltage polarities to be applied were reversed (+100V was applied to two-electrodes side of 2:1, and −100 V was applied toone-electrode side), electric lines of force were supposedly formed witha relative −(negative) bottom at a position in the center of theelectrode width on the one-electrode side.

While this state was maintained, the fine particles were sprayed in thesame manner as Example 1.

As a result, the fine particles were linearly arranged on a position inthe center of the electrode width on one-electrode side.

The conductive fine particles thus arranged were transferred andpress-bonded to a adhesive layer in a manner as shown in FIG. 9 so thata film locally having the conductive fine particles was obtained.

INDUSTRIAL APPLICABILITY

As described above, the fine particle arranging method of the presentinvention makes it possible to arrange fine particles accurately on asurface of an object. Therefore, the liquid crystal display of thepresent invention obtained by using the fine particle arranging methodof the present invention allows most of the spacers to be arrangedbeneath the black matrix. Accordingly, even if light leakage occurs dueto spacers, it gives no adverse effect on the display; thus, it becomespossible to ensure high display quality with good contrast. Moreover, inthe anisotropic conductive film of the present invention obtained byusing the fine particle arranging method of the present invention, theconductive fine particles are placed only on electrode portionsrequiring conductivity.

What is claimed is:
 1. An anisotropic conductive film obtained byarranging conductive fine particles on surface of a film on whichelectrodes are formed, press-bonding an adhesive layer to said film, andexfoliating said film for transferring said arranged fine particles tosaid layer, wherein the step of arranging charged fine particles iscarried out by alternately forming areas having a relatively highelectric potential and areas having a relatively low electric potentialon said surface of said film to form electric lines of force based uponthe areas having the relatively high electrical potential and the areashaving the relatively low electrical potential, and arranging chargedfine particles at a relatively positive bottom position and/or arelatively negative bottom position of said electric lines of force. 2.An anisotropic conductive film obtained by spraying charged fineparticles on a film on which plural electrodes are aligned in order toarrange fine particles on portions other than said electrodes on surfaceof said film, press-bonding an adhesive layer to said film, andexfoliating said film for transferring said arranged fine particles tosaid layer, wherein the step of spraying charged fine particles iscarried out while areas having a relatively high electric potential andareas having a relatively low electric potential are alternately formedon the electrodes by applying voltages having different voltage valuesonto the aligned electrodes; and the application of said voltages havingthe different voltage values to said electrodes is carried out basedupon a constant application pattern in which at least one of arelatively positive bottom position and a relatively negative bottomposition of electric lines of force is made coincident with a gapposition between said plural electrodes, said electric lines of forcebeing formed based upon the voltages having different voltage valuesapplied to the plural electrodes.
 3. An anisotropic conductive filmobtained by spraying charged fine particles on a film comprising stripedelectrodes constituted by aligning plural linear electrodes in order toarrange fine particles on portions other than said linear electrodes onsurface of said film, press-bonding an adhesive layer to said film andexfoliating said film for transferring said arranged fine particles tosaid layer, wherein the step of spraying charged fine particles iscarried out while areas having a relatively high electric potential andareas having a relatively low electric potential are alternately formedon the striped electrodes by applying voltages having different voltagevalues onto said plural linear electrodes aligned with a predeterminedinterval; and the application of said voltages having the differentvoltage values is carried out based upon a constant application patternin which at least one of a relatively positive bottom position and arelatively negative bottom position of electric lines of force is madecoincident with a gap position between said plural linear electrodes,said electric lines of force being formed based upon the voltages havingdifferent voltage values applied to the plural linear electrodes.
 4. Ananisotropic conductive film obtained by spraying charged fine particleson a film on which plural electrodes are aligned in order to arrangefine particle on said electrodes on surface of said film, press-bondingan adhesive layer to said film, and exfoliating said film ortransferring said arranged fine particles to said layer, wherein thestep of spraying charged fine particles is carried out while areashaving a relatively high electric potential and areas having arelatively low electric potential are alternately formed on theelectrodes by applying voltages having different voltage values onto thealigned electrodes; and the application of said voltages having thedifferent voltage values to said electrodes is carried out based upon aconstant application pattern in which at least one of a relativelypositive bottom position and a relatively negative bottom position ofelectric lines of force is made coincident with a gap position betweensaid plural electrodes, said electric lines of force being formed basedupon the voltages having different voltage values applied to the pluralelectrodes.
 5. An anisotropic conductive film obtained by sprayingcharged fine particles on a film comprising striped electrodesconstituted by aligning plural linear electrodes in order to arrangefine particles on said linear electrodes on surface of said film,press-bonding an adhesive layer to said film, and exfoliating said filmfor transferring said arranged fine particles to said layer, wherein thestep of spraying charged fine particles is carried out while areashaving a relatively high electric potential and areas having arelatively low electric potential are alternately formed on the stripedelectrodes by applying voltages having different voltage values ontosaid plural linear electrodes aligned with a predetermined interval; andthe application of said voltages having the different voltage values iscarried out based upon a constant application pattern in which at leastone of a relatively positive bottom position and a relatively negativebottom position of electric lines of force is made coincident with a gapposition between said plural linear electrodes, said electric lines offorce being formed based upon the voltages having different voltagevalues applied to the plural linear electrodes.
 6. A process forproducing an anisotropic conductive film, comprising arranging chargedfine particles on surface of a film on which electrodes are formed,press-bonding an adhesive layer to said film, and exfoliating said filmfor transferring said arranged fine particles to said layer, wherein thestep of arranging charged fine particles is carried out by alternatelyforming areas having a relatively high electric potential and areashaving a relatively low electric potential on said surface of said filmto form electric lines of force based upon the areas having therelatively high electric potential and the areas having the relativelylow electric potential, and arranging charged fine particles at arelatively positive bottom position and/or a relatively negative bottomposition of said electric lines of force.
 7. A process for producing ananisotropic conductive film, comprising spraying charged fine particleson a film on which plural electrodes are aligned in order to arrangefine particles on portions other than said electrodes on surface of saidfilm, press-bonding an adhesive layer to said film, and exfoliating saidfilm for transferring said arranged fine particles to said layer,wherein the step of spraying charged fine particles is carried out whileareas having a relatively high electric potential and areas having arelatively low electric potential are alternately formed on theelectrodes by applying voltages having different voltage values onto thealigned electrodes; and the application of said voltages having thedifferent voltage values to said electrodes is carried out based upon aconstant application pattern in which at least one of a relativelypositive bottom position and a relatively negative bottom position ofelectric lines of force is made coincident with a gap position betweensaid plural electrodes, said electric lines of force being formed basedupon the voltages having different voltage values applied to the pluralelectrodes.
 8. A process for producing an anisotropic conductive film,comprising spraying charged fine particles on a film comprising stripedelectrodes constituted by aligning plural linear electrodes in order toarrange fine particles on portions other than said linear electrodes onsurface of said film, press-bonding an adhesive layer to said film, andexfoliating said film for transferring said arranged fine particles tosaid layer; wherein the step of spraying charged fine particles iscarried out while areas having a relatively high electric potential andareas having a relatively low electric potential are alternately formedon the striped electrodes by applying voltages having different voltagevalues onto said plural linear electrodes aligned with a predeterminedinterval; the application of said voltages having the different voltagevalues is carried out based upon a constant application pattern in whichat least one of a relatively positive bottom position and a relativelynegative bottom position of electric lines of force is made coincidentwith a gap position between said plural linear electrodes, said electriclines of force being formed based upon the voltages having differentvoltage values applied to the plural linear electrodes.
 9. A process forproducing an anisotropic conductive film, comprising spraying chargedfine particles on a film on which plural electrodes are aligned in orderto arrange fine particles on said electrodes on surface of said film,press-bonding an adhesive layer to said film, and exfoliating said filmfor transferring said arranged fine particles to said layer, wherein thestep of spraying charged fine particles is carried out while areashaving a relatively high electric potential and areas having arelatively low electric potential are alternately formed on theelectrodes by applying voltages having different voltage values onto thealigned electrodes; and the application of said voltages having thedifferent voltage values to said electrodes is carried out based upon aconstant application pattern in which at least one of a relativelypositive bottom position and a relatively negative bottom position ofelectric lines of force is made coincident with a gap position betweensaid plural electrodes, said electric lines of force being based uponthe voltages having different voltage values applied to the pluralelectrodes.
 10. A process for producing an anisotropic conductive film,comprising spraying charged fine particles on a film comprising stripedelectrodes constituted by aligning plural linear electrodes in order toarrange fine particles on said linear electrodes on surface of saidfilm, press-bonding an adhesive layer to said film, and exfoliating saidfilm for transferring said arranged fine particles to said layer,wherein the step of spraying charged fine particles is carried out whileareas having a relatively high electric potential and areas having arelatively low electric potential are alternately formed on the stripedelectrodes by applying voltages having different voltage values ontosaid plural linear electrodes aligned with a predetermined interval; andthe application of said voltages having the different voltage values iscarried out based upon a constant application pattern in which at leastone of a relatively positive bottom position and a relatively negativebottom position of electric lines of force is made coincident with a gapposition between said plural linear electrodes, said electric lines offorce being formed based upon the voltages having different voltagevalues applied to the plural linear electrodes.